Image pickup apparatus

ABSTRACT

An image pickup apparatus is provided, which comprises a plurality of image pickup areas formed on a same semiconductor chip and arranged in the horizontal and the vertical directions, each image pickup area having a plurality of pixels arranged in the horizontal and the vertical directions, a plurality of vertical scanning circuits which sequentially scan pixels in the vertical direction to scan a plurality of image pickup areas in the vertical direction independently from each other, a plurality of lenses, at least one of which is provided in each of the plurality of image pickup areas and which focuses light to form an image on the image pickup areas, and a driving circuit which drives the plurality of vertical scanning circuits so that at least a part of a scanning period of each of the plurality of vertical scanning circuits overlaps with each other.

This application is a division of application Ser. No. 09/973,054, filedOct. 10, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image pickup apparatus for pickingup an image of a subject.

2. Related Background Art

An example of a configuration of a conventional solid-state image pickupelement is shown in FIG. 1. In the figure, reference numeral 101 denotespixels having a photoelectric conversion portion such as a photo diode.A pixel area 100 on which an image of a subject is picked up is formedby arranging these pixels two-dimensionally.

In addition, reference numeral 103 denotes vertical signal lines towhich signals from the pixels 101 are read out, 104 denotes storagecapacitors for temporarily accumulating signals read out to the verticalsignal lines 103 from the pixels 101, 105 denotes transfer MOStransistors for transferring the signals read out to the vertical signallines 103 to the storage capacitors 104, and 106 a and 106 b denotetransfer MOS transistors for transferring signals in the storagecapacitors 104 to horizontal signal lines 107.

Moreover, reference numeral 108 denotes a vertical scanning circuit forscanning sequentially in the vertical direction each line of pixels 101in the horizontal direction, thereby controlling to read out signals tothe vertical signal line 103 from the pixels 101 on each line basis.Reference symbols 109 a and 109 b denote horizontal scanning circuitsfor controlling the transfer MOS transistors 106 a and 106 b, therebysequentially reading out the signals accumulated in the storagecapacitor 104 to horizontal signal lines 107 a and 107 b. Referencesymbols 110 a and 109 b denote a reset MOS transistor for resetting thehorizontal signal lines 107 a and 107 b. In addition, reference numeral107 denotes load current sources for forming transistors and sourcefollowers included in the pixels 101.

Here, an arrangement of color filters for a conventional solid-stateimage pickup element will be described. FIG. 2 shows an example of thearrangement, where reference numeral 121 denotes first color filters fortransmitting red light, 122 denotes second color filters fortransmitting green light, and 123 denotes third color filters fortransmitting blue light.

The first color filters 121 and the second color filters 122 arealternately arranged in odd columns starting from the first column ofthe pixel 101, and the second color filters 122 and the third colorfilters 123 are alternately arranged in even columns starting from thesecond column of the pixel 101, which color filters correspond to eachof the pixels arranged two-dimensionally. Moreover, the second colorfilters 122 are arranged such that those in the odd columns and those inthe even columns are not adjacent with each other in the horizontaldirection.

The conventional solid-state image pickup element has the pixel area 100in which a plurality of color filters are arranged as shown in FIG. 2.However, with this method, for example, if a solid-state image pickupelement having 640 pixels horizontally and having 480 pixels verticallyat a pixel pitch of 10 μm is used, a focal distance of a lens giving itsstandard angle of view is 8 mm that is a diagonal length of thesolid-state image pickup element.

Therefore, there is a limitation in making the image pickup apparatusthinner, such as a digital camera upon manufacturing the apparatus usingsuch solid-state image pickup elements.

FIG. 3 shows a solid-state image pickup element that is disclosed inJapanese Patent Application Laid-open No. 62-11264. In FIG. 3,solid-state image pickup areas 2 to 4 for picking up images of threecolor components of R, G and B are formed in one silicon chip 1. Next,configurations and operations of the image pickup areas 2 to 4 will bedescribed using the image pickup area 2 as an example.

In the image pickup area 2, pixels 20 consisting of photodiodes 21 andtransistors 22 for transferring signals generated in the photodiodes 21to vertical output lines 23 are arranged in the horizontal and thevertical directions. Signals outputted to the vertical output lines 23are sequentially outputted from output terminals 25 via horizontaloutput lines by transistors 24 that are on/off controlled by ahorizontal shift register 27.

In addition, the three image pickup areas 2 to 4 are driven by avertical shift register 14 via common reading-out drive line 12.

However, since image pickup areas are arranged one-dimensionally in onedirection in the above-described conventional solid-state image pickupelement, a chip size increases in one direction and a problem arises inmaking the image pickup element compact.

In addition, if an image of a subject is divided into three images by alens and the images are picked up in respective image pickup areas,since an image pickup area 2 and an image pickup area 4 are spacedapart, deviation of images of the subject is caused.

Moreover, since a distance to a vertical shift register is different ineach image pickup area, a control signal to be transmitted in areading-out drive line has a decreased signal level due to a voltagedrop if it is supplied to an image pickup area that is far apart fromthe vertical shift register. As a result, a level of a read out signalmay vary to cause shading or color drift in an image that is finallyobtained.

SUMMARY OF THE INVENTION

The present invention has been devised in view of the above-mentioneddrawbacks, and it is an object of the present invention to reduce a lagof time for accumulating photocharges among image pickup areas.

In addition, it is another object of the present invention to obtain animage with less shading.

In order to attain the above-mentioned objects, according to one aspectof the present invention, an image pickup apparatus is provided, whichcomprises:

a plurality of image pickup areas formed on a same semiconductor chipand arranged in the horizontal and the vertical directions, each imagepickup area having a plurality of pixels arranged in the horizontal andthe vertical directions and a distance between adjacent image pickupareas being larger than a distance between pixels in a same image pickuparea;

a plurality of vertical scanning circuits adapted to sequentially scanpixels in the vertical direction to scan a plurality of image pickupareas in the vertical direction independently from each other; and

a horizontal scanning circuit provided in common for a plurality ofimage pickup areas in the vertical direction, adapted to read outsignals.

In addition, according to another aspect of the present invention, animage pickup apparatus is provided, which comprises:

a plurality of image pickup areas formed on a same semiconductor chipand arranged in the horizontal and the vertical directions, each imagepickup area having a plurality of pixels arranged in the horizontal andthe vertical directions; and

a plurality of vertical scanning circuits adapted to sequentially scanpixels in the vertical direction to scan a plurality of image pickupareas in the vertical direction independently from each other;

wherein the plurality of vertical scanning circuits are provided so asto be adjacent to at least one side of each of the plurality of imagepickup areas.

Other objects, features and advantages of the invention will becomeapparent from the following detailed description taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the presentinvention and, together with the description, serve to explain theprinciples of the present invention, in which:

FIG. 1 is a schematic view showing a configuration of a conventionalsolid-state image pickup element;

FIG. 2 is a view showing a part of the conventional solid-state imagepickup element;

FIG. 3 is a schematic view showing a configuration of the conventionalsolid-state image pickup element;

FIG. 4 is a schematic view showing a configuration of a solid-stateimage pickup element in accordance with a first embodiment of thepresent invention;

FIG. 5 is a circuit diagram of a pixel, a pulse signal output circuitand a line memory of FIG. 1;

FIG. 6 is a schematic plan view showing a configuration of a solid-stateimage pickup element in accordance with a second embodiment of thepresent invention;

FIG. 7 is a schematic view showing a configuration of a solid-stateimage pickup element in accordance with a third embodiment of thepresent invention;

FIG. 8 is a schematic view showing a configuration of a solid-stateimage pickup element in accordance with a fourth embodiment of thepresent invention;

FIG. 9 is a schematic view showing a configuration of a solid-stateimage pickup element in accordance with a fifth embodiment of thepresent invention;

FIG. 10 is a schematic view showing a configuration of a solid-stateimage pickup element in accordance with a sixth embodiment of thepresent invention;

FIG. 11 is a view representing a relation between a solid-state imagepickup element and lenses;

FIG. 12 is a schematic plan view showing a solid-state image pickupelement in accordance with a seventh embodiment of the presentinvention;

FIG. 13 is a schematic plan view showing the solid-state image pickupelement in accordance with the seventh embodiment of the presentinvention;

FIG. 14 is a schematic plan view showing a configuration of a pixel tobe used in the seventh to the ninth embodiments of the presentinvention;

FIG. 15 is a schematic plan view showing the solid-state image pickupelement in accordance with the eighth embodiment of the presentinvention;

FIG. 16 is a schematic plan view showing the solid-state image pickupelement in accordance with the eighth embodiment of the presentinvention;

FIG. 17 is a schematic plan view showing the solid-state image pickupelement in accordance with the ninth embodiment of the presentinvention;

FIG. 18 is a schematic plan view showing the solid-state image pickupelement in accordance with the ninth embodiment of the presentinvention;

FIG. 19 is a schematic plan view showing the solid-state image pickupelement in accordance with a tenth embodiment of the present invention;

FIG. 20 is a plan view showing a configuration of a solid-state imagepickup element;

FIG. 21 is a sectional view showing an arrangement of a pixel group of asolid-state image pickup element and image pickup lenses;

FIG. 22 is a sectional view showing an arrangement of a pixel group of asolid-state image pickup element and image pickup lenses; and

FIG. 23 is a block diagram showing a case in which the solid-state imagepickup element according to any one of the first to the tenthembodiments is applied to a digital camera (image pickup apparatus).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be hereinafterdescribed with reference to the drawings.

FIG. 4 is a schematic view showing a configuration of a solid-stateimage pickup element of a first embodiment of the present invention,components of which are formed on a same semiconductor chip by, forexample, a CMOS process. In FIG. 4, reference numeral 905 denotes pixelshaving a photo diode, 901 to 904 denote image pickup areas in which thepixels 905 are arranged two-dimensionally and R, G1, G2 and B filtersfor forming an image, respectively, are provided, 906 a denotes avertical shift register for outputting a control signal which isgenerated for controlling pixel scanning in the vertical direction inthe image pickup areas 901 and 902, in accordance with a clock signalVCLK2 that is inputted from the outside, 906 b denotes a vertical shiftregister that is signal supplying means for outputting a control signalwhich is generated for controlling pixel scanning in the verticaldirection in the image pickup areas 903 and 904, in accordance with aclock signal VCLK1 that is inputted from the outside, 907 denotes apulse signal output circuit for outputting a pulse signal that drivesthe pixels 905 including a charge or a reading-out pulse for reading outan amplified signal based on charges from the inside of the pixels 905in response to a control signal to be outputted from the vertical shiftregisters 906 a and 906 b, 909 denotes horizontal signal lines fortransmitting a pulse signal to be outputted from the pulse signal outputcircuit 907 to each pixel 905, 912 denotes a vertical signal line fortransmitting charges or the like read out from each pixel 905, 910denotes a line memory for retaining the transmitted charge or the likefor each line, 911 a denotes a horizontal shift register for generatinga control signal to sequentially output the charges read out from theimage pickup areas 901 and 903 among the charges or the like regained inthe line memory 910 to an external processing circuit, and outputtingthe control signal in accordance with a clock signal HCLK1 to beinputted from the outside, 911 b denotes a horizontal shift registerthat is read-out means for generating a control signal to sequentiallyoutput the charges read out from the image pickup areas 902 and 904among the charges or the like retained in the line memory 901 to theexternal processing circuit, and outputting the control signal inaccordance with a clock signal HCLK2 to be inputted from the outside,913 denotes an amplifier that is an output unit for amplifying thecharges or the like outputted form the line memory 910, and 914 denotesan output terminal for outputting the amplified charges or the like tothe processing circuit.

Further, although pixels of three rows and three columns are shown inthe image pickup areas 901 to 904, respectively, in FIG. 4, in order toavoid complexity, in practice, a plurality of pixels according torequired resolution are arranged both in the horizontal direction andthe vertical direction. In addition, a number given to each pixel 905refers to an order of reading out the charges or the like as describedlater.

FIG. 5 is a circuit diagram of the pixel 905, the pulse signal outputcircuit 907 and the line memory 910. In FIG. 5, reference numeral 921denotes photodiodes for converting light to charges, 922 denotestransfer switches for transferring the charges converted by thephotodiodes 921 to floating diffusion areas, 923 denotes MOS transistorsfor obtaining amplified signals based on the transferred charges, 925denotes selection switches for selecting the pixel 905 for reading outthe amplified signal to the vertical signal line 912, and 924 denotesreset switches for resetting a potential of the floating diffusion areasand the photodiodes 921 after the amplified signal is read out.

In addition, in FIG. 5, reference numerals 926 to 928 denote selectionpulse transmitting lines, reset pulse transmitting lines and transferpulse transmitting lines that transmit selection pulses, reset pulsesand transfer pulses for controlling on/off of the selection switches925, the reset switches 924 and the transfer switches 922, respectively,and 931 to 933 denote a transfer pulse generating signal input terminal,a reset pulse generating signal input terminal and a selection pulsegenerating signal input terminal for inputting generating signals thatgenerate a transfer pulse, a reset pulse and a selection pulse to betransmitted through the transfer pulse transmitting lines 928, the resetpulse transmitting lines 927 and the selection pulse transmitting lines926, respectively, 930 denotes AND gates for adding each generatingsignal to be inputted from the transfer pulse generating signal inputterminal 931, the reset pulse generating signal input terminal 932 andthe selection pulse generating signal input terminal 933 and a controlsignal to be outputted from the vertical shift register 906, 934 denotesinput control switches for controlling to input of the charges which areread out to the vertical output line 912, to the line memory 910, 937denotes a control pulse transmitting line for transmitting a controlpulse that controls on/off of the input control switches 934, 935denotes capacitors for accumulating the charges read out to eachvertical output line 912, 936 denotes output control switches forcontrolling output of the charges accumulated in the capacitors 935, and915 denotes input terminals for inputting a control signal from thehorizontal shift register.

Further, the pixel having a MOS type image pickup element as shown inFIG. 5 has an advantage that it is excellent in an automatic exposuremechanism, can realize low power consumption, can be formed by one chipand can be read out nondestructively. However, for example, an amplifiedMOS imager (AMI) image pickup element, a charge modulation device (CMD)and a CCD image pickup element can also be used other than theconfiguration shown in FIG. 2. Note that, for example, when a CCD imagepickup element is used, it is sufficient to arrange a vertical transferCCD and a horizontal transfer CCD instead of the vertical shiftregisters 906 a and 906 b and the horizontal shift registers 911 a and911 b.

Further, the horizontal signal line 909 is provided with the reset pulsetransmitting line 928, the reset pulse transmitting line 927 and theselection pulse transmitting line 926.

Next, operations of FIGS. 4 and 5 will be described. First, light from asubject is condensed on a solid-state image pickup element by an imagepickup lens. Then, when the light enters each photo diode 921 arrangedin a corresponding position in each of the image pickup areas 901 to 904of R, G1, G2 and B, charges are generated.

In this embodiment, as described with reference to FIG. 11 later, theimage of subject is divided into a plurality of images by an imagepickup lens provided in association with each of the image pickup areas901 to 904 and each image is formed on each of the image pickup areas901 to 904.

Thereafter, when control signals outputted from each vertical shiftregister 906 b in accordance with the clock signal VKLC1, respectively,are inputted in the pulse signal output circuit 907 through each inputterminal 929, the pulse signal output circuit 907 generates a transferpulse signal for turning on each transfer switch 922 based on thiscontrol signal and a generated signal which is inputted through thetransfer pulse generating signal input terminal 931, by the AND gate 930and transmits the transfer pulse signal to the pixel 905 side throughthe transfer pulse transmitting lines 928.

Then, for example, the transfer switch 922 of the pixel 905 in eachthird row of the G2 image pickup area 903 and the B image pickup area904 is turned on, and the charges in the photo diode 921 are transferredto the floating diffusion area. Thus, the gate of each MOS transistor923 is turned on by these charges.

Next, when control signals outputted from each vertical shift register906 b in accordance with the clock signal VKLC1, respectively, areinputted into the pulse signal output circuit 907 through each inputterminal 929, the pulse signal output circuit 907 generates a selectionpulse signal for turning on the gate of each selection switch 925 of thepixel 905 from which an amplified signal based on the charges is readout, according to this control signal and a generated signal which isinputted through the selection pulse generating signal input terminal933, by the AND gate 930 and transmits the selection pulse signalthrough the selection pulse transmitting lines 926.

Here, as a number is given to each pixel 905 in the third row of each ofthe image pickup areas 901 to 904, the gate of each selection switch 925of the pixel 905 in the first column of the third row of the G2 imagepickup area 903, the pixel 905 in the first column of the third row ofthe B image pickup area 904, the pixel 905 in the second column of thethird row of the G2 image pickup area 903, the pixel 905 of the secondcolumn of the third row of the B image pickup area 904, the pixel 905 inthe third column of the third row of the G2 image pickup area 903 andthe pixel 905 in the third column of the third row of the B image pickuparea 904 is turned on.

In this way, the amplified signal obtained by each MOS transistor 923 isread out to each vertical signal line 912. Further, in each pixel 905from which the amplified signal is read out, each reset switch 924 isturned on by a reset pulse signal which is generated by the AND gate 930based on the control signals outputted from each vertical shift register906 b, respectively, in accordance with the clock signal VKLC1 and ageneration signal to be inputted through the reset pulse generatingsignal input terminal 932, and potentials of each floating diffusionarea and each photo diode 921 is reset.

On the other hand, the amplified signal read out to each vertical signalline 912 is accumulated in each capacitor 935 of the line memory 910when the input control switch 934 is turned on in response to a signaltransmitted through the control pulse transmitting line 937.

Thereafter, control signals for sequentially outputting the amplifiedsignals accumulated in each capacitor 935 to the outside are generatedin each of the horizontal shift registers 911 a and 911 b and outputtedto the line memory 910, respectively, in accordance with the clocksignals HCLK1 and HCLK2. Here, if high and low of the clock signalsHCLK1 and HCLK2 are made to appear alternately, each output controlswitch 936 is sequentially turned on in the order of reading out theamplified signals of each pixel 905 and the amplified signalsaccumulated in the line memory 910 are outputted to the outside.

Similarly, the amplified signal is read out from each pixel 905 in thethird row of the R image pickup area 901 and the G1 image pickup area902. Subsequently, the amplified signals from each pixel 905 in thesecond row of the G2 image pickup area 903 and the B image pickup area904, each pixel 905 in the second row of the R image pickup area 901 andthe G1 image pickup area 902, each pixel 905 in the first row of the G2image pickup area 903 and the B image pickup area 904 and each pixel 905in the first row of the R image pickup area 901 and the G1 image pickuparea 902 are outputted to the outside, respectively.

As described above, in this embodiment, two vertical shift registers 906a and 906 b are provided in the vertical direction, respectively,whereby a time difference caused when outputting a signal read out fromthe pixel 905 arranged in a position corresponding to each of the imagepickup areas 901 to 904 to a processing circuit, is reduced to a timedifference equivalent to that in outputting a signal of pixels 905 onone line.

That is, if a signal is outputted from the next image pickup area aftera signal from one image pickup area is outputted with respect to theimage pickup areas arranged in the vertical direction, a time foraccumulating photoecharges varies significantly between the two imagepickup areas in the vertical direction, which adversely affects a finalimage.

For example, if pixels are arranged in m lines in each image pickuparea, that is, pixels of 2m lines are arranged for an entire solid-stateimage pickup element, there is a time difference equivalent to a timedifference in outputting control signals for pixels of m lines from themoment when control signals are outputted to pixels in the i-th (1≦i≦m)line of the R image pickup area to the moment when control signals areoutputted to pixels in the i-th (1≦i≦m) of the G2 image pickup area. Thedifference of time period in accumulation of photocharges between thetwo image pickup areas in the vertical direction is nearly eliminated bythe operation of this embodiment described above.

In addition, in this embodiment, since signals are alternately outputtedfor each pixel from different image pickup areas in reading out signalsaccumulated in the line memory, processing in a processing circuit in alater stage becomes easy.

In addition, in this embodiment, since an amplifier or the like is notprovided for each image pickup area but is provided in common for fourimage pickup areas, for example, dispersion or the like for eachamplifier is eliminated and it becomes possible to obtain a satisfactoryimage.

FIG. 6 is a schematic view showing a configuration of a solid-stateimage pickup element of a second embodiment of the present invention,components of which are formed in a same semiconductor chip by the CMOSprocess or the like. In FIG. 6, reference symbols 910 a and 911 b denoteline memories for accumulating charges or the like read out from thepixels 905 arranged in the R image pickup area 901 and the G1 imagepickup area 902, respectively, and 911 c to 911 f denote horizontalshift registers for sequentially outputting charges or the like read outfrom the R image pickup area 901, the G1 image pickup area 902, the G2image pickup area 903 and the B image pickup area 904 among the chargesor the like retained in the line memories 910 a and 911 b to an externalprocessing circuit. Further, in FIG. 6, parts similar to those shown inFIG. 4 are given identical reference numerals.

In addition, operations of the solid-state image pickup element shown inFIG. 6 are similar to those shown in FIG. 4. However, as numbered inFIG. 6, control signals to be generated in the vertical shift registers906 a and 906 b are outputted to a processing circuit in the followingorder when attention is paid to the pixels 905 arranged in the third rowof each image pickup areas 901 to 904: for example, amplified signalsfrom the pixels 905 in the first column of the third row of the G2 imagepickup area 903 and amplified signals from the pixels 905 in the firstcolumn of the third row of the R image pickup area 901 aresimultaneously outputted, amplified signals from the pixels 905 in thefirst column of the third row of the B image pickup area 904 andamplified signals from the pixels 905 in the first column of the thirdrow of the G1 image pickup area 902 are outputted simultaneously next,amplified signals from the pixels 905 in the second column of the thirdrow of the G2 image pickup area 903 and amplified signals from thepixels 905 of the second column of the third row of the R image pickuparea 901 are outputted simultaneously next, and amplified signals fromthe pixels 905 in the second column of the third row of the B imagepickup area 904 and amplified signals from the pixels 905 in the secondcolumn of the third row of the G1 image pickup area 902 are outputtedsimultaneously next.

Moreover, amplified signals read out from the pixels 905 arranged in theR image pickup area 901 and accumulated in the line memory 910 a areoutputted to the processing circuit in response to a control signalgenerated by the horizontal shift register 911 c. Amplified signals readout from the pixels 905 arranged in the G1 image pickup area 902 andaccumulated in the line memory 910 a are outputted to the processingcircuit in response to a control signal generated by the horizontalshift register 911 d.

Similarly, amplified signals read out from the pixels 905 arranged inthe G2 image pickup area 903 and accumulated in the line memory 901 bare outputted to the processing circuit in response to a control signalgenerated by the horizontal shift register 911 e. Amplified signals readout from the pixels 905 arranged in the B image pickup area 904 andaccumulated in the line memory 910 f are outputted to the processingcircuit in response to a control signal generated by the horizontalshift register 911 d.

As described above, in this embodiment, two vertical shift registers 906a and 906 b are provided in the vertical direction, respectively,whereby a time difference caused when outputting a signal read out fromthe pixel 905 arranged in a position corresponding to each of the imagepickup areas 901 to 904 to a processing circuit is eliminated.

That is, if a signal is outputted from the next image pickup area aftera signal from one image pickup area is outputted with respect to theimage pickup areas arranged in the vertical direction, a time foraccumulating photocharges varies significantly between the two imagepickup areas in the vertical direction, which adversely affects a finalimage.

For example, if pixels are arranged in m lines in each image pickuparea, that is, pixels of 2m lines are arranged for an entire solid-stateimage pickup element, there is a time difference equivalent to a timedifference in outputting control signals for pixels of m lines from thetime when control signals are outputted to pixels in the i-th (1≦i≦m)line of the R image pickup area until the time when control signals areoutputted to pixels in the i-th (1≦i≦m) of the G2 image pickup area. Thedifference of time period in accumulating photocharges between the twoimage pickup areas in the vertical direction is completely eliminated bythis embodiment.

In addition, in this embodiment, since signals are alternately outputtedfor each pixel from different image pickup areas in reading out signalsaccumulated in the line memory, processing in a processing circuit in alater stage becomes easy. In the above-mentioned embodiments, adifference of time period in accumulating photocharges in the same linebetween image pickup areas is reduced and a satisfactory image can beobtained. In addition, since a plurality of image pickup areas arearranged two-dimensionally, it becomes possible to make a chip sizecompact and at the same time to reduce deviation of images if an imageof a subject is divided into a plurality of image pickup areas and animage is formed on each image pickup area.

FIG. 7 is a schematic view showing a configuration of a solid-stateimage pickup element of a third embodiment of the present invention. InFIG. 7, reference numeral 905 denotes pixels having photoelectricconversion element, and 901 to 904 denote image pickup areas of R, G1,G2 and B in which the pixels 905 are arranged two-dimensionally to forman image, respectively, the four image pickup areas being configured tobe arranged two-dimensionally. Reference symbols 906 a to 906 d denotevertical shift registers for controlling timing for supplying a controlsignal for reading out an amplified signal that is based on a chargefrom each pixel 905 arranged in each of the image pickup areas 901 to904, respectively, 909 denotes horizontal signal lines for supplying acontrol signal to each pixel 905, 912 denotes vertical signal lines fortransmitting an amplified signal read out from each pixel 905, and 911 ato 911 d denote horizontal shift registers for sequentially controllingthe transfer of amplified signals read out to the vertical signal lines912 to an external processing circuit, respectively.

Further, the image pickup areas 901 to 904 of R, G1, B and G2 areconfigured in terms of optical design such that, for example, the Rimage pickup area 901 provided with an R filter and the B image pickuparea 904 provided with a B filter are arranged orthogonally, and the G1image pickup area 902 provided with a G1 filter and the G2 image pickuparea 903 provided with a G2 filter are arranged orthogonally. Here, aspecific configuration of each pixel 905 is identical with the pixel 905in FIG. 5.

Next, operations of FIG. 7 will be described. First, an image of asubject is divided into four images by image pickup lenses, which areprovided in association with each of the image pickup areas 901 to 904,respectively, and the images are focused on each of the image pickupareas 901 to 904. Then, when light enters each photo diode 921 arrangedin a corresponding position in each of the image pickup areas 901 to 904of R, G1, G2 and B, charges are generated. Thereafter, when eachtransfer switch 922 is turned on, the charges in each photo diode 921are transferred to each floating diffusion area. Thus, the gate of eachMOS transistor 923 is turned on by these charges.

Next, when control signals from the vertical shift registers 906 a to906 d turn on the gate of the selection switch 925 that is selected toread out an amplified signal through each horizontal signal line 909, anamplified signal obtained by the MOS transistor 923 is read out to eachvertical signal line 912. Further, in each pixel 905 from which anamplified signal is read out, each reset switch 924 is turned on andpotentials of each floating diffusion area and each photo diode 921 arereset.

As shown in FIG. 7, the solid-state image pickup element of thisembodiment is provided with the vertical shift registers 906 a to 906 dand the horizontal shift registers 911 a to 911 d, respectively, foreach of the image pickup areas 901 to 904, supplies a control signalsimultaneously to each pixel 905 in a corresponding position from eachof the vertical shift registers 906 a to 906 d and further transfers anamplified signal read out from each pixel 905 to a processing circuit bythe horizontal shift registers 911 a to 911 d.

In particular, as shown in FIG. 7, for example, when the vertical shiftregisters 906 a to 906 d are arranged on the left and the horizontalshift registers 911 a to 911 d are arranged below each of the imagepickup areas 901 to 904, distances between respective pixels 905 in acorresponding position of each of the image pickup areas 901 to 904 andthe vertical shift registers 906 a to 906 b are equal. Thus, a level ofa control signal transmitted through the horizontal signal line 909 isnot susceptible to an effect caused by a voltage drop.

FIG. 8 is a schematic view showing a configuration of a solid-stateimage pickup element of a fourth embodiment of the present invention. InFIG. 8, the vertical shift registers 906 a to 906 d and the horizontalshift registers 911 a to 911 d are arranged to surround each of theimage pickup areas 901 to 904, respectively. Further, in FIG. 8, partssimilar to those in FIG. 7 are given the identical reference symbols.

Note that, it is preferable that an image pickup lens is provided foreach image pickup area such that light incident into each of the imagepickup areas 901 to 904 forms an image on the pixel 905 positioned atthe center of each of the image pickup areas 901 to 904. It is alsopreferable that such each pixel 905 is close to a point of intersectionof a line connecting the pixel 905 positioned in the center of the Rimage pickup area 901 with the pixel 905 positioned in the center of theB image pickup area 904 and a line connecting the pixel 905 positionedin the center of the G1 image pickup area 902 with the pixel 905positioned in the center of the G2 image pickup area 903.

In other words, it is preferable that the image pickup areas 901 to 904are arranged to be close to each other. This is because, for example, ifa distance from a subject to each of the image pickup areas 901 to 904becomes short, since an image to be obtained is different based oncharges from each of the image pickup areas 901 to 904, an image is notfinally obtained unless complicated supplementation or the like isperformed.

Thus, as shown in FIG. 8, the vertical shift registers 906 a to 906 dand the horizontal shift registers 911 a to 911 d are arranged tosurround each of the image pickup areas 901 to 904, respectively,whereby each of the image pickup areas 901 to 904 are close to eachother.

FIG. 9 is a schematic view showing a configuration of a solid-stateimage pickup element of a fifth embodiment of the present invention. InFIG. 9, reference symbols 911 e and 911 f denote horizontal shiftregisters that are provided in common with respect to each pixel 905 ofthe R image pickup area 901 and the G2 image pickup area 903 and eachpixel 905 of the G1 image pickup area 902 and the B image pickup area904, respectively. Further, in FIG. 9, parts similar to those in FIG. 7are given the identical reference numerals.

Note that, as described above, although it is preferable that the imagepickup areas 901 to 904 are provided to be close to each other, theimage pickup areas 901 to 904 need to be always spaced apart from eachother. This is because a diameter of an image pickup lens to be providedabove each of the image pickup areas 901 to 904 needs to be made longerthan a length of one side of each of the image pickup areas 901 to 904in order to cause light from a subject to enter the image pick up areas901 to 904.

Thus, as shown in FIG. 9, in this embodiment, the horizontal shiftregisters 911 e and 911 f are provided in common with respect to eachpixel 905 of the R image pickup area 901 and the G2 image pickup area,respectively, and space formed between the R image pickup area 901 andthe G2 image pickup area 903 and space formed between the G1 imagepickup area 902 and the B image pickup area 904 are effectivelyutilized. As a result, the solid-state image pickup element isminiaturized.

Further, this embodiment is described with reference to the case inwhich the horizontal shift registers 911 e and 911 f are provided incommon with respect to each pixel 905 of the R image pickup area 901 andthe G2 image pickup area 903, respectively, as an example. However,vertical shift registers may be provided in common with respect to eachpixel 905 of the R image pickup area 901 and the G1 image pickup area902 and each pixel 905 of the G2 image pickup area 903 and the B imagepickup area 904, respectively, or the vertical shift registers 906 b and906 d may be arranged on the right sides of the G1 image pickup area 902and the B image pickup area 904.

FIG. 10 is a schematic view showing a configuration of a solid-stateimage pickup element of a sixth embodiment of the present invention.Reference symbols 906 e and 906 f denote vertical shift registers thatare provided in common with respect to each pixel 905 of the R imagepickup area 901 and the G1 image pickup area 902 and each pixel 905 ofthe G1 image pickup area 903 and the B image pickup area 904,respectively. Further, in FIG. 10, parts similar to those in FIG. 9 aregiven identical reference numerals.

In this way, in this embodiment, the vertical shift registers 906 e and906 f and the horizontal shift registers 911 e and 911 f are arrangedamong the image pickup areas 901 to 904, and spaces formed among theimage pickup areas 901 to 904 are effectively utilized, whereby thesolid-state image pickup element is miniaturized.

In the above-described third to sixth embodiments, operations forreading out a signal from each image pickup area are the same as thosedescribed in the previous embodiments. In addition, although omitted inFIGS. 7 to 10, the line memory denoted as 910 in FIG. 5 is practicallyarranged between each of the horizontal shift register 911 and each ofthe image pickup areas 901, 902, 903 and 904.

As described above, when the solid-state image pickup element describedin each embodiment of the present invention is used in a digital cameraor the like, it becomes possible to make it compact and crosstalk isreduced. Therefore, a high quality image can be obtained.

In addition, in each embodiment, a plurality of image pickup areas,vertical shift registers and horizontal shift registers, which arearranged two-dimensionally, are formed on a same semiconductor chip bythe CMOS process or the like.

In addition, although a color filter arrangement of a primary colorBayer is described in each embodiment, other arrangements, for example,a complementary color filter arrangement may be used.

The above-described third to sixth embodiments have the followingeffects in addition to the effects of the first and the secondembodiments.

A solid-state image pickup element is configured so as to have a signalsupplying means for supplying signals to pixels in an image pickup areaon at least one side in a periphery of each of a plurality of imagepickup areas, whereby shading or color heterogeneity in an image can beeliminated.

Moreover, in addition to the above-mentioned configuration, at least onevertical shift register is independently provided in each of a pluralityof image pickup areas, whereby a remarkable effect is realized in thathigh speed driving becomes possible, for example, a problem of not beingable to follow up an image pickup operation when picking up a movingimage is eliminated.

Matters common to seventh to tenth embodiments will be hereinafterdescribed.

In an image pickup apparatus such as a digital camera in which an imageformation lens is arranged on a solid-state image pickup element tofocus light from a subject by the image formation lens and convert thelight to an electric signal by the solid-state image pickup element,positioning of an image formation center of the image formation lens anda center of a pixel area of the solid-state image pickup element hasbeen performed.

However, the above-mentioned positioning of the image formation centerof the image formation lens in the image pickup apparatus and the centerof the pixel area of the solid-state image pickup element is not alwayseasy work, and in the case in which high accuracy positioning isstructurally required, more complicated work is required.

A characteristic of the seventh to the tenth embodiments described belowis that it is made possible to highly accurately and efficiently adjustthe center of the pixel area of the solid-state image pickup element andthe center of the image pickup lens upon assembling the solid-stateimage pickup element and the image pickup lens.

The inventor of the present invention examined a compound-eye typesolid-state image pickup apparatus that is provided with a plurality ofimage pickup lenses, focuses light from an image pickup object by eachimage pickup lens onto a two-dimensional sensor having photoelectricconversion elements and processes an output signal from thetwo-dimensional sensor in an image processing unit to form an image.

FIG. 10 is a schematic view showing a configuration of an example of theabove-mentioned image pickup apparatus. In FIG. 10, reference numeral901 denotes image pickup lenses for focusing light from an image pickupobject onto pixel groups 902 a to 902 d provided with each color filterof R, G1, G2 and B, and 903 denotes a solid-state image pickup elementprovided with a plurality of photoelectric conversion elements.Compound-eye image pickup can be performed by providing each filter ofR, G1, G2 and B therewith.

The scope of the present invention is not specifically limited to theabove-mentioned image pickup apparatus. However, in the compound-eyetype image pickup apparatus, fine tuning for aligning the center of eachimage pickup area of R, G1, G2 and B and the image formation center byimage pickup lenses is more difficult compared with a single-eye imagepickup apparatus upon assembling the compound-eye type solid-state imagepickup element and a plurality of image pickup lenses for focusing lightfrom the image pickup object onto the solid-state image pickup elements.As a result, efficiency of assembly may be lowered. Thus, since anadjustment method other than an optical path adjustment can be providedby configuration of the seventh to the tenth embodiments to behereinafter described, the configuration can be preferably applied tothe case of compound-eye type.

FIGS. 12 and 13 are schematic views showing a configuration of asolid-state image pickup element of a seventh embodiment of the presentinvention. FIG. 12 is a plan view of the solid-state image pickupelement of this embodiment, which shows so-called four-eye type. Asshown in FIG. 11, the solid-state image pickup apparatus is configuredwith the image pickup lenses (image formation optical system) arrangedin front of the solid-state image pickup element.

In FIG. 12, reference numerals 101 and 102 denote image pickup areas inwhich photoelectric conversion elements for converting incident light toan electric signal are arranged two-dimensionally. More specifically,reference symbols 101 a to 101 d denote pixel groups, 102 denotes pixelgroups (which will be redundant pixel groups) provided in the linedirection for adjusting a position of the center of the pixel groups ofthe solid-state image pickup element, and 103 denotes one pixel formingthe pixel groups 101 a to 101 d. In the figure, “+” shows an imageformation center of each image pickup lens and “x” shows the center ofeach pixel group.

FIG. 13 is a plan view showing the case in which the solid-state imagepickup elements of FIG. 12 have reading out circuits. In FIG. 13,reference symbols 101 a to 101 d denote pixel groups (in the figure,reference symbols 101 b to 101 d are omitted), 102 denotes pixel groupsprovided in the line direction for adjusting a position of the center ofthe pixel groups of the solid-state image pickup element, 203 denoteshorizontal shift registers (HSRs) for reading out outputs from the pixelgroups, 204 denotes vertical shift registers (VSRs) for reading outoutputs from the pixel groups, and 205 denotes amplifiers for amplifyingthe outputs read out from the pixel groups. The pixel groups 101 a to101 d and 102 are configured from the pixels as shown in FIG. 3.

FIG. 14 is an equivalent circuit diagram showing a configuration of thepixel 103. Reference numeral 301 denotes a photo diode forphotoelectrically converting incident light, 302 denotes a transferswitch for transferring an electric signal to a floating diffusion (FD)area, 303 denotes a reset switch for resetting charges of the floatingdiffusion (FD) area, 304 denotes a MOS transistor for obtaining anamplified signal, where the floating diffusion (FD) area and the gateare connected to each other, and 305 denotes a vertical output line foroutputting signal charges.

An electric signal is transferred from the photo diode 301 to thefloating diffusion area by the vertical shift registers (VSRs) 204 shownin FIG. 13 and amplified by the MOS transistor 304, and then theelectric signal is outputted to the vertical output line 305. The signalis read out from the vertical output line 305 to the amplifiers 205 bythe horizontal shift registers (HSRs) 203 of FIG. 2 and amplified.

The image pickup apparatus of this embodiment has the four pixel groups101 a to 101 d provided with four filters of R, G1, G2 and B and causesincident light to enter the pixel 103 forming each pixel group 101 a to101 d through image pickup lenses.

When assembling the solid-state image pickup element as shown in FIG. 12and image pickup lenses, in order to align the center of each pixelgroup and the center of each image pickup lens, an effective pixel rangeis set from the pixel group 101 a and the pixel group 102 provided inthis embodiment, whereby it becomes possible to easily align the centerof each pixel group and the center of each image pickup lense andefficiency in the assembly can be increased. This is effective forassembly with large deviation in the horizontal direction in thisembodiment. In addition, the pixels that are not used as effectivepixels among the pixels of the pixel group 102 also photoelectricallyconvert incident light to output electric signals. The optical outputsignals are read out by the vertical shift registers 204 and thehorizontal shift registers 203, amplified by the amplifiers 205 andoutputted to a signal processing unit for forming an image. However, itis sufficient to idly read the signals from the pixels not used as imageinformation and not to take them in as image information. Then, signalsfrom the pixels used as image information is subjected to variousprocessing such as color processing and processed signals are outputtedto a display (displaying means), a memory or the like.

In addition, any sensor such as an amplified MOS imager (AMI), a chargemodulation device (CMD) and a CCD may be used other than a so-calledCMOS sensor shown in FIG. 14.

This embodiment is appropriately used in the case in which alignment ofa center of pixel groups of a solid-state image pickup element and animage forming center of image pickup lenses in the line direction isdifficult. For example, as shown in FIG. 20, if a width of a selectionoxide film area 110 dividing the pixel group is larger in the columndirection than in the row direction, that is, if a width of a selectionoxide film area divining the R pixel group and the G2 pixel group aswell as the G1 pixel group and the B pixel group is made larger than awidth of a selection oxide film area dividing the R pixel group and theG1 pixel group as well as the G2 pixel group and the B pixel group, thearrangement of the pixel groups and the image pickup lenses is as shownin FIGS. 12 and 13.

When a positional relation between the image forming lenses and thepixel groups of the solid-state image pickup element is viewed from theY direction of FIG. 20, the distance between the image pickup lenses isshortened because the width of the selection oxide film is small asshown in FIG. 21. Here, for example, if an image is formed on the Bpixel group adjacent the G2 pixel group by the image pickup lense 111that originally plays the role of forming an image on the G2 pixelgroup, a phenomenon called smear is caused. Therefore, in the horizontaldirection (row direction) in which the width of the selection oxide filmdividing the R pixel group and the G1 pixel group as well as the G2pixel group and the B pixel group is small, it is necessary to highlyaccurately adjust positions of the optical center by the image pickuplense 111 and the center of each pixel group. On the other hand, whenthe positional relation between the image pickup lenses and the pixelgroups of the solid-state image pickup element is viewed from the Xdirection of FIG. 20, the distance between the image pickup lensesbecomes large because the width of the selection oxide film is large asshown in FIG. 22. In this case, light that should form an image on acertain pixel group is less likely to form an image on an adjacent pixelgroup thereto. Therefore, accuracy of a positional adjustment of theoptical center by the image pickup lenses and the center of each pixelgroup may be lower in the vertical direction (column direction) in whichthe width of the selection oxide film dividing the R pixel group and theG2 pixel group as well as the G1 pixel group and the B pixel group thanin the horizontal direction (row direction).

Thus, in the configuration shown in FIG. 20, since alignment of thecenter of the pixel groups of the solid-state image pickup element andthe image formation center of the image pickup lenses is difficult inthe horizontal direction (row direction) of the pixel groups, and it isdesirable to provide the redundant pixel groups 102 shown in FIG. 12 inthe horizontal direction.

Further, a circuit (analog/logic), a GND or the like may be provided ina LOCOS area in the vertical and the horizontal directions.

In addition, in some cases, the selection oxide film dividing the Rpixel group and the G1 pixel group as well as the G2 pixel group and theB pixel group is not formed and the R pixel group and the G1 pixel groupas well as the G2 pixel group and the B pixel group are formed adjacentto each other.

In an eighth embodiment to be described later, an example in which aredundant pixel group is provided in the column direction will bedescribed. This is also preferably used in the case in which alignmentof a center of pixel groups of a solid-state image pickup element and animage formation center of image pickup lenses is difficult in the columndirection (vertical direction) of the pixel groups.

FIGS. 15 and 16 are schematic views showing a configuration of asolid-state image pickup element of an eighth embodiment of the presentinvention. FIG. 15 is a plan view of the solid-state image pickupelement of this embodiment and shows a so-called four-eye typesolid-state image pickup element. As shown in FIG. 11, an image pickupapparatus is configured with image pickup lenses arranged in front ofthe solid-state image pickup element.

In FIG. 15, reference numerals 401 and 402 denote image pickup areas inwhich photoelectric conversion elements for converting incident light toan electric signal are arranged two-dimensionally. More specifically,reference symbols 401 a to 401 d denote pixel groups, 402 denotes pixelgroups (which will be redundant pixel groups) provided in the columndirection for adjusting a position of the center of the pixel groups ofthe solid-state image pickup element, and 403 denotes one pixel formingthe pixel groups 401 a to 401 d. The pixel configuration is the same asthat shown in FIG. 14. In the figure, “+” shows an image formationcenter of each image pickup lens and “x” shows the center of each pixelgroup.

FIG. 16 is a plan view showing the case in which the solid-state imagepickup elements of FIG. 15 have reading out circuits. In FIG. 16,reference symbols 401 a to 401 d denote pixel groups (in the figure,reference symbols 401 b to 401 d are omitted), 402 denotes pixel groupsprovided in the column direction for adjusting a position of the centerof the pixel groups of the solid-state image pickup element, 503 denoteshorizontal shift registers (HSRs) for reading out outputs from the pixelgroups, 504 denotes vertical shift registers (VSRs) for reading outoutputs from the pixel groups, and 505 denotes amplifiers for amplifyingthe outputs read out from the pixel groups. An electric signal istransferred from the photo diode to the floating diffusion area by thevertical shift registers (VSRs) 504 shown in FIG. 16 and amplified bythe MOS transistor, and then the electric signal is outputted to thevertical output line. The signal is read out by the horizontal shiftregisters (HSRs) 503 of FIG. 16 and amplified by the amplifiers 505.

The image pickup apparatus of this embodiment has the four pixel groups401 a to 401 d provided with four filters of R, G1, G2 and B and causesincident light to enter the pixel 403 forming each pixel group 401 a to401 d through image pickup lenses.

When assembling the solid-state image pickup element as shown in FIG. 15and image pickup lenses, in order to align the center of each pixelgroup and the center of each image pickup lens, an effective pixel rangeis set from the pixel group 401 a and the pixel group 402 provided inthis embodiment, whereby it becomes possible to easily align the centerof each pixel group and the center of each image pickup lense andefficiency of assembly can be increased. This is effective for assemblywith large deviation in the horizontal direction in this embodiment. Inaddition, the pixels that are not used as effective pixels among thepixels of the pixel group 402 also photoelectrically convert incidentlight to output electric signals. The optical output signals are readout by the vertical shift registers 504 and the horizontal shiftregisters 503, amplified by the amplifiers 505 and outputted to a signalprocessing unit for forming an image. However, it is sufficient to idlyread the signals from the pixels not used as image information and notto take them in as image information. Then, signals from the pixels usedas image information is subjected to various processings such as colorprocessing and processed signals are outputted to a display, a memory orthe like.

In addition, any sensor such as an amplified MOS imager (AMI), a chargemodulation device (CMD) and a CCD may be used other than a so-calledCMOS sensor shown in FIG. 14.

FIGS. 17 and 18 are schematic views showing a configuration of asolid-state image pickup element of a ninth embodiment of the presentinvention. FIG. 17 is a plan view of the solid-state image pickupelement of this embodiment and shows a so-called four-eye typesolid-state image pickup element. As shown in FIG. 11, an image pickupapparatus is configured with image pickup lenses arranged in front ofthe solid-state image pickup element.

In FIG. 17, reference numerals 601 and 602 denote image pickup areas inwhich photoelectric conversion elements for converting incident light toan electric signal are arranged two-dimensionally. More specifically,reference symbols 601 a to 601 d denote pixel groups, 602 denotes pixelgroups (which will be redundant pixel groups) provided in line andcolumn directions for adjusting a position of the center of the pixelgroups of the solid-state image pickup element, and 603 denotes onepixel forming the pixel groups 601 a to 601 d. The pixel configurationis the same as that shown in FIG. 14. In FIG. 17, “+” shows an imageformation center of each image pickup lens and “x” shows the center ofeach pixel group.

FIG. 18 is a plan view showing the case in which the solid-state imagepickup element of FIG. 17 has reading out circuits. In FIG. 18,reference symbols 601 a to 601 d denote pixel groups (in the figure,reference symbols 601 b to 601 d are omitted), 602 denotes pixel groupsprovided in row and column directions for adjusting a position of thecenter of the pixel groups of the solid-state image pickup element, 703denotes horizontal shift registers (HSR) for reading out outputs fromthe pixel groups, 704 denotes vertical shift registers (VSR) for readingout outputs from the pixel groups, and 705 denotes amplifiers foramplifying the outputs read out from the pixel groups.

An electric signal is transferred from the photo-diode to the floatingdiffusion area by the vertical shift registers (VSR) 704 shown in FIG.18, and amplified by the MOS transistor, and then the electric signal isoutputted to the vertical output line. The signal is read out by thehorizontal shift registers (HSR) 703 of FIG. 18 and amplified by theamplifiers 705.

The image pickup apparatus of this embodiment has the four pixel groups601 a to 601 d provided with four filters of R, G1, G2 and B and causesincident light to enter the pixel 603 forming each pixel group 601 a to601 d through image pickup lenses.

In assembling the solid-state image pickup element as shown in FIG. 17and image pickup lenses, in order to align the center of each pixelgroup and the center of each image pickup lens, an effective pixel rangeis set from the pixel group 601 a and the pixel group 602 provided inthis embodiment, whereby it becomes possible to easily align the centerof each pixel group and the center of each image pickup lense andefficiency of assembly can be increased. This is effective for assemblywith large deviation in the horizontal and vertical directions in thisembodiment. In addition, the pixels that are not used as effectivepixels among the pixels of the pixel group 602 also photoelectricallyconvert incident light to output electric signals. The photo outputsignals are read out by the vertical shift registers 704 and thehorizontal shift registers 703, amplified by the amplifiers 705 andoutputted to a signal processing unit for forming an image. However, itis sufficient to idly read the signals from the pixels that are not usedas image information and not to take them in as image information. Then,signals from the pixels used as image information are subjected tovarious processing such as color processing and processed signals areoutputted to a display, a memory or the like.

In addition, any sensor such as an amplified MOS imager (AMI), a chargemodulation device (CMD) and a CCD may be used other than a so-calledCMOS sensor shown in FIG. 14.

FIG. 19 is a plan view of a configuration of a tenth embodiment in whicha solid-state image pickup element has a reading out circuit. In FIG.19, reference numerals 801 and 802 denote image pickup areas in whichphotoelectric conversion elements for converting incident light to anelectric signal are arranged two-dimensionally. More specifically,reference numeral 801 denotes pixel groups, 802 denotes pixel groups(which will be redundant pixel groups) provided for adjusting a positionof the center of the pixel groups of the solid-state image pickupelement, 803 denotes horizontal shift registers (HSRs) for reading outoutputs from the pixel groups, 804 denotes vertical shift registers(VSRs) for reading out outputs from the pixel groups, 805 denotesamplifiers for amplifying the outputs read out from the pixel groups,806 denotes horizontal decoders for reading out outputs from the pixelgroups, which are provided for adjusting a position of the center of thepixel groups in the horizontal direction, and 807 denotes verticaldecoders for reading out outputs from the pixel groups, which areprovided for adjusting a position of the center of the pixel groups inthe vertical direction. An electric signal is transferred from the photodiode to the floating diffusion area by the vertical shift registers(VSRs) 804 and the vertical decoders 807, and amplified by the MOStransistor, and then the electric signal is outputted to the verticaloutput line. The signal is read out by the horizontal shift registers(HSRs) 803 and the horizontal decoder 806 and amplified by theamplifiers 805.

The image pickup apparatus of this embodiment has the four pixel groupsprovided with four filters of R, G1, G2 and B and causes incident lightto input into the pixel forming each pixel group through image pickuplenses. In assembling the solid-state image pickup element and imagepickup lenses, an effective pixel range is set from the pixel group 801provided for aligning the center of each pixel group and the center ofeach image pickup lens and the pixel group 802 provided in thisembodiment, whereby it becomes possible to easily align the center ofeach pixel group and the center of each image pickup lense andefficiency of assembly can be increased. This is effective for assemblywith large deviation in the horizontal or the vertical direction in thisembodiment. In addition, outputs are read out from the pixel group 801by the horizontal shift registers and the vertical shift registers andonly pixels to be used an effective pixel among the pixel group 802 areread out by the horizontal decoders and the vertical decoders, whereby areading out time of outputs from the solid-state image pickup apparatuscan be shortened. Thereafter, processing for forming an image in asignal processing unit is performed. Then, a processed signal isoutputted to a display, a memory or the like.

If a pixel group like the pixel group 801 provided for aligning thecenter of each pixel group and the center of each image pickup lens isprovided in the row direction, in order to align the center of eachpixel group and the center of each image pickup lens, an effective pixelrange is set from the pixel group 801 and the pixel group 802 providedin this embodiment, whereby it becomes possible to easily align thecenter of each pixel group and the center of each image pickup lense andefficiency of assembly can be increased. If a pixel group like the pixelgroup 802 is provided in the horizontal direction in this embodiment,this is effective for a method of assembly with large deviation in thehorizontal direction. In addition, if a pixel group like the pixel group802 is provided in the vertical direction, this is effective forassembly with large deviation in the vertical direction. Further, if apixel group like the pixel group 802 is provided in the horizontal andthe vertical direction, this is more effective for assembly with largedeviation in the horizontal direction and the vertical direction.

In addition, any sensor such as an amplified MOS imager (AMI), a chargemodulation device (CMD) and CCD may be used other than a so-called CMOSsensor shown in FIG. 14.

An eleventh embodiment that is the case in which the solid-state imagepickup element of the present invention is applied to a still camerawill be described in detail with reference to FIG. 23.

FIG. 23 is a block diagram showing the case in which the solid-stateimage pickup element of any one of the first to the tenth embodiments isapplied to a digital still camera (image pickup apparatus).

In FIG. 23, reference numeral 1 denotes a barrier functioning as both aprotect and a main switch for a lens, 2 denotes a lens for forming anoptical image of a subject on a solid-state image pickup element 4, 3denotes an iris for varying an amount of light that passed through thelens 2, and 4 denotes a solid-state image pickup element for picking upthe image of the subject formed by the lens 2 as an image signal.Further, the solid-state image pickup element 4 is a compound-eye typesolid-state image pickup element and has four image pickup areasprovided with the above-mentioned color filters of R, G1, G2 and B. Asshown in FIG. 11, the lens 2 is provided in association with each imagepickup area. Reference numeral 6 denotes an A/D converter for performinganalog-digital conversion of an image signal outputted from thesolid-state image pickup element 4, 7 denotes a signal processing unitfor applying various corrections to image data outputted from the A/Dconverter 6 and compressing data, 8 denotes a timing generation unit foroutputting various timing signals to the solid-state image pickupelement 4, an image pickup signal processing circuit 5, the A/Dconverter 6 and the signal processing unit 7, 9 denotes a system controland operation unit for controlling various operations and the entiredigital still camera, 10 denotes a memory unit for temporarily storingimage data, 11 denotes an interface unit for recording or reading outimage data in or from a recording medium, 12 denotes a detachablerecording medium such as a semiconductor memory for recording or readingout image data, and 13 denotes an interface unit for communicating withan external computer or the like.

Next, operations of the digital still camera of the afore-mentionedconfiguration at the time of photographing will be described.

When the barrier 1 is opened, a main power source is turned on, a powersource of a control system is turned on next and a power source of animage pickup system circuit such as the A/D converter 6 is furtherturned on. Subsequently, in order to control an amount of exposure, thesystem control and operation unit 9 opens the iris 3. A signal outputtedfrom the solid-state image pickup element 4 is converted by the A/Dconverter 6 and then inputted into the signal processing unit 7. Then,an operation for exposure is performed by the system control andoperation unit 9. Here, in the seventh to the ninth embodiments,processing as described below is performed in the signal processing unit7.

In the signal processing unit 7, as described in the first embodiment,for example, pixels that are not used as effective pixels among thepixels of the image pickup area 102 also photoelectrically convertincident light and output electric signals. The photo output signals areread out by the vertical shift registers 204 and the horizontal shiftregisters 203, amplified by the amplifier 205 and outputted to thesignal processing unit 7. Signals from pixels not used as imageinformation are idly read in the signal processing unit 7 and aresubjected to processing for not taking them as image information. Then,signals from pixels used as image information are subjected to variouskinds of processing such as color processing. The operation for exposureis performed in the system control and operation unit 9 based on thedata of the processing.

Brightness is determined based on a result of this photometry and thesystem control and operation unit 9 controls the iris 3 according to theresult.

Next, a high frequency component is extracted from the signal outputtedfrom the solid-state image pickup element 4 to calculate a distance to asubject in the system control and operation unit 9. Thereafter, the lens2 is driven to determine if it is at a focusing position or not and, ifit is determined that the lens 2 is not at the focusing position, thelens 2 is driven again to perform measurement of the distance. Then, themain exposure is started after the in-focus is confirmed.

When the exposure ends, the image signal outputted from the solid-sateimage pickup element 4 is A/D converted by the A/D converter 6, sentthrough the signal processing unit 7 and written into the memory unit 10by the system control and operation unit 9.

Thereafter, data accumulated in the memory unit 10 is sent through therecording medium control I/F unit 11 and recorded in the detachablerecording medium 12 such as a semiconductor memory by the control of thesystem control and operation unit 9.

In addition, processing of an image may be performed by inputting thedata directly into a computer or the like through the external I/F unit13.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

1. A solid state image pickup apparatus, comprising: a plurality ofpixel areas arranged two-dimensionally, each of the pixel areas having aphotoelectric conversion element for converting an incident light intoan electric signal; and an optical focusing system for focusing theincident light into each of the pixel areas, wherein at least one of thepixel areas has a redundant pixel group at an inner periphery areawithin the at least one of the pixel areas, and has an effective pixelarea at an inside of the redundant pixel group, and wherein when a focuscenter position of the optical focusing system and the center positionof a group of the pixels are misaligned, an output signal from theredundant pixel group is used.
 2. An image pickup system comprising thesolid state image pickup apparatus according to claim 1, and a signalprocessing circuit for processing the electric signal from the solidstate image pickup apparatus.